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Intermediate SQL

SQL GROUP BY Clause in a SELECT Query

So far the query results are record-oriented, meaning each row in the result corresponds to one record in the table. The SQL `GROUP BY` clause opens up the possibility that queries have a row in the result representing a group of records. Plus, it enables you to use grouping functions: functions that return some result () calculated in the group of records such as the sum, average or quantity.

Aggregate Functions in SQL

This lesson is connected to the previous lesson [SQL GROUP BY Clause in a SELECT Query](/sql-tutorial/intermediate-sql/sql-group-by-clause/). In fact, you used some aggregate functions in the `GROUP BY` examples. This lesson covers aggregate functions with and without the `GROUP BY` clause.

SQL Having Clause

This lesson covers the SQL `HAVING` clause, which is a complementary clause to the `GROUP BY` clause. The `HAVING` clause acts as a filter at the group level. If you think of WHERE as a filter clause oriented to records, then `HAVING` is a filter clause oriented to groups of records created with the `GROUP BY` clause.

SQL Subqueries: The Super Powerful SQL Feature

In this lesson you explore the Subqueries, the super powerful and flexible feature of the `SQL` language. SQL Subqueries can be used in the `SELECT`, `INSERT`, `UPDATE`, and `DELETE` statements. This lesson focuses on using subqueries in the [SELECT statement](/sql-tutorial/basic-sql/sql-select-from-where-statement/).

SQL DISTINCT Clause

The SQL `DISTINCT` clause is used to discard duplicate records from the results of a query. You have seen it in action in the [Aggregation](/sql-tutorial/intermediate-sql/sql-aggregate-functions) and [Subqueries](/sql-tutorial/intermediate-sql/sql-subquery) lessons. Now it is time to look at more details. From a syntax point of view the `DISTINCT` clause must be before the first element in the `SELECT` list of columns:

SQL Date and Time Functions and Data Types

SQL databases provide data types related to date and time data, as you learned in the [SQL Data Types](/sql-tutorial/basic-sql/sql-data-types) lesson. Now you can see the details of how these data types are related, how to create expressions involving different date data types and use some SQL date and time functions.

SQL String Functions

SQL databases provide several [SQL Data Types](/sql-tutorial/basic-sql/sql-data-types) related to text strings such as `VARCHAR`, `CHAR`, and `TEXT`. In this lesson you explore some string functions and operators to manipulate string data.

SQL GROUP BY Clause in a SELECT Query

So far the query results are record-oriented, meaning each row in the result corresponds to one record in the table. The SQL `GROUP BY` clause opens up the possibility that queries have a row in the result representing a group of records. Plus, it enables you to use grouping functions: functions that return some result () calculated in the group of records such as the sum, average or quantity.

Aggregate Functions in SQL

This lesson is connected to the previous lesson [SQL GROUP BY Clause in a SELECT Query](/sql-tutorial/intermediate-sql/sql-group-by-clause/). In fact, you used some aggregate functions in the `GROUP BY` examples. This lesson covers aggregate functions with and without the `GROUP BY` clause.

SQL Having Clause

This lesson covers the SQL `HAVING` clause, which is a complementary clause to the `GROUP BY` clause. The `HAVING` clause acts as a filter at the group level. If you think of WHERE as a filter clause oriented to records, then `HAVING` is a filter clause oriented to groups of records created with the `GROUP BY` clause.

SQL Subqueries: The Super Powerful SQL Feature

In this lesson you explore the Subqueries, the super powerful and flexible feature of the `SQL` language. SQL Subqueries can be used in the `SELECT`, `INSERT`, `UPDATE`, and `DELETE` statements. This lesson focuses on using subqueries in the [SELECT statement](/sql-tutorial/basic-sql/sql-select-from-where-statement/).

SQL DISTINCT Clause

The SQL `DISTINCT` clause is used to discard duplicate records from the results of a query. You have seen it in action in the [Aggregation](/sql-tutorial/intermediate-sql/sql-aggregate-functions) and [Subqueries](/sql-tutorial/intermediate-sql/sql-subquery) lessons. Now it is time to look at more details. From a syntax point of view the `DISTINCT` clause must be before the first element in the `SELECT` list of columns:

SQL Date and Time Functions and Data Types

SQL databases provide data types related to date and time data, as you learned in the [SQL Data Types](/sql-tutorial/basic-sql/sql-data-types) lesson. Now you can see the details of how these data types are related, how to create expressions involving different date data types and use some SQL date and time functions.

SQL String Functions

SQL databases provide several [SQL Data Types](/sql-tutorial/basic-sql/sql-data-types) related to text strings such as `VARCHAR`, `CHAR`, and `TEXT`. In this lesson you explore some string functions and operators to manipulate string data.

SQL GROUP BY Clause in a SELECT Query

So far the query results are record-oriented, meaning each row in the result corresponds to one record in the table. The SQL `GROUP BY` clause opens up the possibility that queries have a row in the result representing a group of records. Plus, it enables you to use grouping functions: functions that return some result () calculated in the group of records such as the sum, average or quantity.

Aggregate Functions in SQL

This lesson is connected to the previous lesson [SQL GROUP BY Clause in a SELECT Query](/sql-tutorial/intermediate-sql/sql-group-by-clause/). In fact, you used some aggregate functions in the `GROUP BY` examples. This lesson covers aggregate functions with and without the `GROUP BY` clause.

SQL Having Clause

This lesson covers the SQL `HAVING` clause, which is a complementary clause to the `GROUP BY` clause. The `HAVING` clause acts as a filter at the group level. If you think of WHERE as a filter clause oriented to records, then `HAVING` is a filter clause oriented to groups of records created with the `GROUP BY` clause.

SQL Subqueries: The Super Powerful SQL Feature

In this lesson you explore the Subqueries, the super powerful and flexible feature of the `SQL` language. SQL Subqueries can be used in the `SELECT`, `INSERT`, `UPDATE`, and `DELETE` statements. This lesson focuses on using subqueries in the [SELECT statement](/sql-tutorial/basic-sql/sql-select-from-where-statement/).

SQL DISTINCT Clause

The SQL `DISTINCT` clause is used to discard duplicate records from the results of a query. You have seen it in action in the [Aggregation](/sql-tutorial/intermediate-sql/sql-aggregate-functions) and [Subqueries](/sql-tutorial/intermediate-sql/sql-subquery) lessons. Now it is time to look at more details. From a syntax point of view the `DISTINCT` clause must be before the first element in the `SELECT` list of columns:

SQL Date and Time Functions and Data Types

SQL databases provide data types related to date and time data, as you learned in the [SQL Data Types](/sql-tutorial/basic-sql/sql-data-types) lesson. Now you can see the details of how these data types are related, how to create expressions involving different date data types and use some SQL date and time functions.

SQL String Functions

SQL databases provide several [SQL Data Types](/sql-tutorial/basic-sql/sql-data-types) related to text strings such as `VARCHAR`, `CHAR`, and `TEXT`. In this lesson you explore some string functions and operators to manipulate string data.

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